Despite the corruption and lobbying scandals that ensnared Republicans in Congress and triggered a Democratic resurgence over the past decade, Tom DeLay has only one piece of advice for GOP leaders as they attempt to retake the House in the upcoming midterm elections: Be more aggressive.

"The biggest change that I think they need [is] to be more aggressive at turning back the Obama agenda," the former House majority leader told ABC News Chief Investigative Correspondent Brian Ross in a lengthy, wide ranging interview on this week's episode of "Brian Ross Investigates."

Tom DeLay: End of DOJ Investigation 'Bittersweet'

The interview was conducted after the Justice Department informed DeLay it would be dropping its six-year probe into his conduct in office.

The Hammer Talks Washington Politics

Combative and unbowed, the man who was once known as simply "The Hammer," defended his relationship with disgraced former lobbyist Jack Abramoff. He said the two remain close friends and spoke just last month, shortly after Abramoff was released from federal prison and moved into a Baltimore halfway house. Asked what the two discussed, DeLay said, "None of your business."

The former majority leader decried the ugly nature of Washington politics, upbraided Democrats, and blamed "bureaucrats" in the U.S. Justice Department for letting politics and personal vendettas drive their case against him, saying "they hung this cloud over my head for six years."

And he criticized the media – including ABC News -- for creating what he said was an impression that political corruption is far more widespread than it really is.

Tom DeLay: Republicans Need to Be More Aggressive

"It's not bad enough now to just beat them at policy or let them ruin your reputation," DeLay said. "They've got to bankrupt you, ruin your family, put you in jail, put you in the grave, and then dance on your grace. That's not good for the country."

The Texas Republican also did not rule out a return to elected office.

"I don't know what the Lord has in store for me," he smiled when asked if he would ever run again.

Perhaps the most striking moment of the 20-minute interview came when Ross asked DeLay if he felt there were any lessons to take from the Abramoff scandal and an era in which free-spending lobbyists lavished members of congress with meals, trips, and campaign donations.

Tom DeLay on the Jack Abramoff Scandal

Delay and Ross have tangled repeatedly over the years, as ABC News traveled to the South Pacific to show the then-majority leader embracing Abramoff and being feted by his clients. ABC News also captured some of the first footage of the famously lavish DeLay fundraising events at the Republican National Convention – events which had historically been closed to the public.

Asked if money had been a negative force in Washington, DeLay said he did not think it was.

"I don't believe it. I was good at raising it. And I used it to advance the conservative cause," he said. "Money can corrupt corruptible people, [but] most people are not corrupt."